I've changed the overall design as posted here: http://forums.solydxk.nl/viewtopic.php?f=77&t=6038
It took me some time to get KDE5 in the EEs to look something SolydXK-worthy but it's done.
At the moment, grizzler is building new EEs with the latest updates.

I'd like to go live with all the ISOs and new configuration packages at once. So, if you want you can already update the localized ISOs with the new design.

The updated packages are in testing. So, there is a slight difference in updating the ISOs.
This is how you can update them :

Use the appropriate attachment to overwrite boot/isolinux/splash.jpg

Install the latest solydxk-constructor if you use the Constructor to build the ISOs: